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Weird behavior when trying to build a fully static binary with MUSL (x86_64-unknown-linux-musl) #79624
Description
I'm new with rust, just started playing around with it.
Output of rustc --version --verbose:
rustc 1.48.0 (7eac88abb 2020-11-16)
binary: rustc
commit-hash: 7eac88abb2e57e752f3302f02be5f3ce3d7adfb4
commit-date: 2020-11-16
host: x86_64-unknown-linux-gnu
release: 1.48.0
LLVM version: 11.0
Basically I'm not getting an executable-format(it's still executable tho, more like a lib) output binary when I specify x86_64-unknown-linux-musl as the target. This is what I ran:
cargo build --release --target x86_64-unknown-linux-muslAfter that on checking the output executable with file, I get the following:
ruston: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=be7ffcac4063277b96b8eeeba2adf0d3a02fcfe3, stripped
Also on running ldd:
statically linked
While if I run cargo build --release --target i686-unknown-linux-musl, I kinda get my expected results.
file output:
ruston: ELF 32-bit LSB executable, Intel 80386, version 1 (GNU/Linux), statically linked, BuildID[sha1]=5160d9b8fb9616aba4ecb05ce9e9d56638fdf187, stripped
ldd output:
not a dynamic executable
I'm sorry if I've misunderstood anything and thanks in advance :)
Tl;dr: x86_64-unknown-linux-musl build target is generating ELF LSB shared object (dynamically linked) while i686-unknown-linux-musl is making ELF LSB executable (statically linked) binary.
Activity
petrochenkov commentedon Dec 2, 2020
This happens because
static_position_independent_executablesis enabled in https://github.com/rust-lang/rust/blob/master/compiler/rustc_target/src/spec/x86_64_unknown_linux_musl.rs but not in https://github.com/rust-lang/rust/blob/master/compiler/rustc_target/src/spec/i686_unknown_linux_musl.rs.(
static_position_independent_executableswas enabled in #70740, not sure why it was done forx86_64only.)Static PIE is reported as "dynamically linked" by
file.axonasif commentedon Dec 2, 2020
So, is there anything I could do regarding this issue ?
Maybe compiling the rust-compiler with
static_position_independent_executablesdisabled in the.rsfile as you specified would help ? Although, it seems like a complicated process 😅Thanks!
petrochenkov commentedon Dec 2, 2020
I don't think anything needs to be done here?
(Besides enabling
static_position_independent_executablesfori686-unknown-linux-muslperhaps.)This
is the expected behavior, static position-independent executables are indeed executables, but they may confuse tools like
filewhich may report them as dynamic libraries.axonasif commentedon Dec 3, 2020
Okay so, that means I got nothing to worry about, right ?
petrochenkov commentedon Dec 4, 2020
Right, closing as not-an-issue.
plusls commentedon Jan 13, 2023
I am wonder that why it only enable
static_position_independent_executablesfor x86_64 but no enable in i686, although i686 don't support pic instruction, but can implement it by call and get return addr(in fact, gcc use it to implement pic in i686), so I think we can think i686 support pic, so we should enablestatic_position_independent_executablesfor it ?I just want to build a i686 musl pie executeable file, but i found it link the crtbegin but not crtbeginS, and I finally found that
static_position_independent_executablesis false in i686 target.